Hey Janis,
Are you asking for specific cases that would require it?
If so: http://forum.mikrotik.com/t/draft-ipv6-authentication-for-hotspots/38359/1 (Wow this guy is awesome, what a great script right? 
)
Would be really helpful if I could assign dynamic address list entries for any ipv6 addresses seen locally by the router.
In this case I’m already using the comment field to store the mac address however so I’ll work on storing a time value in there along with it and scrape the time data from it like that periodically.
Your point is valid however wouldn’t it make just as much sense to use the pre-existing ability to remove address-list entries rather than running / scheduling my own for everything? 
Side notes re IPv6 address list:
[admin@Router] > ipv6 firewall address-list print
Flags: X - disabled, D - dynamic
# LIST ADDRESS
0 test 2001:470:8902:1::2/128
[admin@Router] > ip firewall address-list print
Flags: X - disabled, D - dynamic
# LIST ADDRESS
0 D ssh_blacklist 94.102.9.202
Will the ipv6 address-list continue to have the mask applied to single addresses?
Just noticed it when writing the above script so when comparing addresses to the address list I have to include the /128 in my code explicitly to match them
It also would appear that the new ipv6 address-list doesn’t support ranges, will this be added in future?